UK spent £4bn on drone warfare.

Britain’s Ministry of Defence (MoD) has spent £4 billion ($6.5 billion) to amass a force of 657 military drones despite the controversy over the secrecy of its deadly drone strikes overseas, a new report reveals.

The fleet includes 10 MQ-9 Reaper drones, which are armed with laser-guided bombs and Hellfire missiles and are capable to hover 20,000 feet above targets for over 20 hours, The Sunday People r eported.

The news comes a month after the MoD opened the doors of its Royal Air Force (RAF) Waddington base, which is being used as a control centre for the country’s controversial drone attacks in Afghanistan.

The Raft Waddington airbase in Lincolnshire is home to XIII Squadron, the team that operates Britain’s largest and only armed drone known as the Reaper.

The first Reaper operations from British soil started on April 24, 2013, at the airbase.

Access to the airbase was granted after months of negotiation for transparency over the deployment of remote-controlled unmanned warfare overseas.